Supplement Inflatable Restraint System (SRS) also known as safety airbag is a standard equipment for automobiles, which is provided for protecting passengers or drivers in case of a car accident, and the SRS is capable of inflating an airbag quickly (approximately 0.1 second) to provide a buffering space for protecting passengers from being hit or injured in the car accident.
There are three main methods of inflating the automobile airbags as described below. 1. A full high-pressure air inflator uses a pressurized gas stored in an air cylinder as a gas source for inflating the airbag, and such inflator has the drawbacks of requiring a relatively larger gas storage and pressure, and thus causing greater volume, thickness and weight of the air cylinder and incurring a higher cost and more limitation on its application.
2. A pyrotechnic inflator fills propellant therein, such that when the propellant in the inflator is struck, the igniter will ignite the propellant to produce gas and fill up an airbag. However, such inflator has the drawback of producing a high temperature gas which may damage the airbag easily or burn or injure the passengers, and the solid residue and toxic gases remained after the combustion jeopardize our health and environment.
3. A hybrid inflator improves over the drawbacks of the aforementioned two types of inflators, wherein propellant is ignited to produce high-pressure gas mixed with a room-temperature pressurized gas in an air cylinder, so as to achieve the effects of the aforementioned two types of inflators, preventing accidents caused by the too-high temperature, and providing an easier installation due to the smaller and lighter air cylinder. In addition, the air cylinder with a lower pressure may reduce the cost effectively.
However, such hybrid inflator is limited by the amount of propellants and the sealing degree and technology of the pressurized gas cylinder. Many factors must be taken into consideration to produce airflow with sufficient pressure while having the capability of releasing the mixed high pressure gas appropriately if the seal plate at the mouth of the air cylinder cracks and assuring the sufficient airtightness and safety at normal use of the air cylinder in order to achieve the most appropriate and safety conditions. The conventional inflator generally comes with a structure that may not be disposed a narrow space easily, and thus is lack of practicability. Based on the foregoing reasons, the inventor of the present invention designed a hybrid inflator of an airbag, in hope of overcoming the drawbacks of the prior art and improving the industrial application.